It's not surprising this scene ended up on the cutting room floor. Even Oliver Stone's source for the yarn, author Jim Marrs, acknowledges that medical science deems this "murder" impossible.(2) It is true that Jack Ruby did make the claim that he had been injected with cancer cells, but one simply could not develop cancer from such injections. In fact, injections of cancer cells have been used experimentally in humans in attempts to boost the immune system.

Ruby also claimed that his prison cell was being poisoned with mustard gas, and that genocide against the Jews was being conducted in the very building in which he was incarcerated. Jews were being exterminated not far from his cell, he said, and he asserted that could hear their screams. Is Oliver Stone about to argue that Ruby is a credible source of information about such things?

Just as importantly, and despite popular mythology, Jack Ruby did not die of cancer. As Stone's source, Jim Marrs, also acknowledges, Ruby had been diagnosed with lung cancer, but the cause of his death was pulmonary embolism; a blood clot had formed in a leg, passed through his heart and lodged in his lung.(3)

At one point in JFK, investigator Lou Ivon (Jay O. Sanders) insists that Ruby's death is part of a coordinated campaign to silence conspiracy witnesses: "how many corpses you lawyers gotta see to figure out what's going on?" he says.(4)
Oliver Stone claims to have done his homework. How does he explain nonsense like this?

1. Oliver Stone and Zachary Sklar, JFK: The Book of the Film (New York: Applause, 1992), p. 60. All quotations are from the shooting script and may vary slightly from the finished motion picture. While omitted from the theatrical release and director's cut, this segment is included with the DVD release of JFK.